Leaky, unsightly faucets are a fairly common problem, but with a few simple tools—and the willingness to wedge yourself under a sink for a little while—swapping one out for a brand new faucet is a simple project to DIY.

I really should say, the principles of changing out a faucet are simple. In fact, Installing a faucet on a new sink is one of the easiest DIY projects you can do. The trick, of course, is that you often have to remove an old faucet before you can install a new one, and this is usually quite challenging. You might find yourself trying to remove nuts that have rusted in place and can only be accessed by wedging half of your body into a tiny little cabinet full of pipes and parts and tools.

Some of my most creative swearing has happened while wedged in a cabinet underneath a sink. However, in my experience, a shiny new faucet (particularly one you installed yourself) is always worth the effort.

As with any DIY project, your own under-the-sink situation will probably have its own quirks, but understanding the basics of how a new faucet is installed may help you assess (and problem-solve, if needed) your project.

Step One: Check Under the Sink

In almost all cases you will see these things under a sink:

A PVC drain line that carries used water away from the sink. There may be multiple lines that tie together.

Two (or more) water supply lines. Typically a faucet receives water from both a cold line and a hot line that runs from your water heater. These lines will often be some kind of rigid material—copper, galvanized pipe, or PEX, among others— as they enter the cabinet. They are usually attached to a shut-of-valve (oval knob) and above the valve you may find rigid lines, or, in more recent construction, flexible lines that run up to the faucet.

Depending on your particular situation you may see things like additional water lines running from a purifier, a disposal, or other drain lines. Tracing the lines to their origin and testing where water flows from while opening and closing valves and faucets may help you better understand what's going on under your sink.

Step Two: Remove the Existing Faucet

Before you start to remove the existing faucet, shut off the water at the valves under the sink. Test existing faucet and make sure nothing is running before you disconnect the lines.

There are two sets of nuts up by the faucet. The first holds the water supply line in place (and is almost always metal) the second set are usually larger (and may be plastic in newer faucets) and hold the faucet to the sink.

I strongly recommend using a basin wrench to remove the nuts to the supply lines. Here's a great video explaining how a basin wrench works.

I've removed faucets using whatever pliers/wrenches I had on hand, and I can tell you the basin wrench makes the job infinitely easier.

You may also use the basin wrench to remove the mounting nuts, or they may be plastic with tabs that can be loosened by hand.

In theory, this is all you need to do to remove the faucet, although you may need to work at getting a few of those nuts loose. (I've been known to take a hammer to a rusted-on faucet a time or two… not the most elegant solution, but some projects call for brute force.)

Step Three: Install Your New Faucet

Installing a new faucet is basically the reverse of taking out the old one (unless you use the hammer method, of course).

The new faucet is attached to the sink with mounting nuts. Here's an example, the large plastic piece is the mounting nut that will be screwed on (by hand) under the sink.

There is also usually some kind of plastic gasket that will sit between the faucet and the sink. This may be different depending on faucet type and sink material—every faucet configuration is a bit different, of course, so it's important to understand the principles of how the faucet connects and apply them to your own project—but instructions should be provided with any faucet you purchase.

Supply lines should then be reattached both at the faucet, and at the shut off valves. Using Teflon tape on the threads of any connections can help make a water-tight seal. Applying Teflon tape is as easy as wrapping the tape around the threaded part of the pipe, but if it's your first time doing this, you might want to check out the video at this link to see how it's done.

Here's a video that shows the complete process of removing and installing faucet, and a few different tool options.

There are a few things to note that might make your faucet installation job easier.

Look at the configuration of the holes on your sink before purchasing a new faucet. Sinks can have anywhere from one to four holes, and there is different spacing on those holes to accommodate different faucet styles. (Here's a guide from Peerless that shows possible configurations.) If the faucet you want fits your sink but leaves open holes, most big-box stores sell hole plugs that will cover unused holes.

I favor Delta brand faucets in particular because most models contain supply lines that run all the way from inside the faucet to the shut-off valves, eliminating the need for flexible supply lines that need to be attached up at the faucet. They are easier to install, and one less connection means one less spot for possible leaks.